JPS60111886A - Flame spraying burner - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Applications!) The present invention relates to a burner for a refractory thermal spraying device used as a refractory lining repair device for furnace walls or molten metal containers.

(Prior art) This type of thermal spraying equipment sprays refractory powder together with flame from a burner toward the furnace wall repair area for thermal spray repair. Due to this use, flashback, a phenomenon in which the flame flows back into the burner, may occur. This backfire occurs when the combustion speed of the combustible gas ejected from the burner is higher than the gas ejection speed. Specifically, it occurs when a blockage occurs in the burner's crater, causing the gas to swell. When the ejection speed becomes slower, when the combustion speed increases due to a rise in gas temperature, or when the gas flow rate or pressure changes,
It may also occur if something collides with the crater or the crater is blocked due to incorrect operation while moving the burner.

If a backfire occurs, there is a risk of damage to the inside of the bar, making it impossible to continue work, or causing a serious accident. The supply pulp in the supply line was closed manually or by remote control, and the supply of flammable gas and combustion-supporting gas was stopped.

However, if it is done by an operator, it is difficult to stop the gas supply instantly, and there is a possibility that a serious disaster may occur.

Of course, it is ideal to prevent flashbacks from occurring at all, and for example, when thermal spraying is used, as in the device described in Japanese Utility Model Publication No. 56-31332, flashbacks are prevented at the end of thermal spraying. Since flashbacks occur due to various factors as mentioned above, including during work, it is extremely difficult to fundamentally prevent flashbacks from occurring. Therefore, there is currently a demand for the development of a device that can instantly stop flashback.

(Object of the Invention) The present invention provides a method for instantly detecting flashback using a flashback detection device installed in a fuel tank, and thereby supplying both flammable fluid and combustible gas, or The object of the present invention is to provide a thermal spray nozzle which can instantly extinguish flashbacks by stopping the supply of spray only.

(Configuration and Effect of the Invention) The first aspect of the present invention is to connect a flammable fluid supply line and a combustion-supporting gas supply line to a barred mouth part through a mixing part, and to Connect the inert gas supply line to the combustion-supporting gas supply line, and connect the inert gas or a mixed gas supply line of inert gas and combustion-supporting gas to the combustion-supporting gas supply line, and detect flashback using the flashback detection device installed in the no-cooner. When this occurs, the detection signal operates the control valves of each of the supply lines to supply inert gas instead of flammable fluid to the flammable fluid supply line, and combustible gas to the combustible gas supply line. It is characterized by supplying an inert gas or a mixed gas of an inert gas and a combustion-supporting gas instead of the gas.

The invention of writing 2 connects the flammable fluid supply line and the combustion-supporting gas supply line to the burner mouth part through the mixing part, and also provides an inverse combustion system in which the burner has a movable body that operates υ due to the pressure increase at the time of flashback. A fire detection device is installed in which the check valve of the combustion-supporting gas supply line is linked to the mobile body, and when a flashback occurs, the check valve is instantly closed by the operation of the mobile body, and the combustion-supporting gas is supplied. It is characterized by stopping.

Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 schematically shows the configuration of a thermal spraying device, which includes a gas supply device 1. It is equipped with a control machine 2° and a thermal spraying machine 3.

Further details will be given based on an embodiment in which the first invention and the second invention are implemented simultaneously in order to improve safety. FIG. 2 shows an example of the embodiment, and in the figure, the supply device 1 includes a flammable gas (for example, propane gas) supply section 5.
Combustion-supporting gas (oxygen) supply section 6. Inert gas supply section 7
．． A supply unit (not shown) for supplying powder such as refractory powder is provided. The combustible gas supply section 5 includes a supply pipe 11. It is connected to a mixing section 13 in the thermal spraying machine 3 via a supply path 12 in the controller 2 and the like. The combustion-supporting gas supply section 6 includes a supply pipe 15. It is connected to the mixing section 13 via a supply path 16 in the controller 2 and the like. Mixing section 1
3 is connected to the inlet of a burner pipe 170. Although not shown, the powder supply section is similarly connected to a powder inlet near the gunner pipe 17 via a supply path in the supply pipe controller 2.

The inert gas supplies 7 are each connected via a supply line 20.21 to the inlet of an inert gas supply line 22.23 in the controller 2. The outlet of the inert gas supply path 22 is connected to the middle of the flammable fluid supply path 12. Further, the outlet of the inert gas supply path 23 is connected to the middle of the combustion-supporting gas supply path 16.

The combustible gas supply path 12 is provided with a valve V1 at a portion upstream of the connection point of the inert IF gas supply path 22. The combustion-supporting gas supply path 16 is also provided with a valve V2 upstream from the connection point of the inert gas supply path 23 (at the part II).Valves V are also provided in the middle of the inert gas supply path 22 and 23, respectively.
3, V, is provided.

These valves v1 to v4 are, for example, electric, magnetic, etc.
It is electrically connected to the controller 25. Further, a temperature sensor 26 is connected to the controller 25, and this temperature sensor 2
The sensor 27 of No. 6 also protrudes into the mixed gas passage 29 on the downstream side of the mixing section 13.

The base end of the burner pipe 170 is connected to a substantially cylindrical burner housing 31 via a burner pipe joint 30 as shown in No. 31.
It is fitted and fixed to the inner periphery of the tip. Joint 300 large diameter rear half (portion opposite to burner pipe 17) and housing 3
There is an 0 cylinder 32 on the inner circumference of the first half (the part near the tip) of 1.
．． A mixing tube 35 is fitted and fixed via 33. The mixing tube 35 has a small diameter hole 36 in the front part and a medium diameter hole 37 in the middle part.
The rear portion 38 is provided with a large diameter hole 39.

A rod-shaped actuating body 41 is slidably fitted into the inner circumferential surface of the medium-diameter hole 37 via a 017 ring 40 . The rod-shaped movable body 41 is provided with a large-diameter portion 42 at a portion protruding into the large-diameter hole 39, and the large-diameter portion 42 is slidably fitted into the inner peripheral surface of the large-diameter hole 39. From the center of the large diameter portion 42 is a cylindrical portion 43.
is protruding backwards. An annular end wall 45 is provided at the rear end of the mixing tube 35, and a cylindrical portion 46 that protrudes rearward from the inner periphery of the end wall 45 is slidably fitted onto the outer periphery of the cylindrical portion 43. It matches. The mixing tube cylindrical portion 46 has an end wall 4 that closes the rear end opening.
7, and the end wall 47 has a socket IJ ring 49 (
The rear end of the compression coil spring) is in pressure contact. The spring 49 is provided within the cylindrical portion 43 of the operating body, and its front end is in pressure contact with the cylindrical portion 43. A support 50 projects from the center of the end wall 47 in a direction opposite to the spring 49.

An annular spring stopper 51 is fixed to the rear end of the seat 50 by a nut 48. Spring stopper 51
The rear end of the valve spring 52 (compression coil spring) is in pressure contact with the valve spring 52 (compression coil spring). The front end of the spring 52 is pressed against an outward flange 55 at the front end of the cylindrical valve 53. The cylindrical valve 53 is slidably fitted to the outer periphery of the cylindrical portion 46 .

As shown in the partially enlarged explanatory view of FIG. 4, a hole 56 with a slightly larger diameter is provided on the inner periphery of the front portion of the valve 53. FIG. 4 shows a normal state, in which the inner surface of the rear end of the hole 56 (the inclined cam surface 57) is in contact with the seal 59 from behind. A plurality of goals 59' are arranged in an annular shape, and each of the goals is accommodated in a hole in the cylindrical portion 46 of the mixing tube. An annular groove 60 is provided on the outer peripheral surface of the cylindrical portion 43 of the actuating body, and in a normal state, the groove 60 is located somewhat in front of the ball 59. As is clear from the above explanation, sl-le 59
The cylindrical valve 53 is prevented from moving forward by the elasticity of the spring 52, and the flange end face of the cylindrical valve 53 is separated from the end wall 45 in a normal state.

Next, the passage structure for combustible gas and combustion-supporting gas will be explained. The combustible gas supply line 12 and the combustion-supporting gas supply line 16 are connected to the passages 61, 64 in FIG. 3.

A plurality of combustible gas passages 61 are provided, each extending through the housing 31 from the rear end to the filter chamber 62 at the front. The filter chamber 62 is formed by an annular groove provided on the inner peripheral surface of the housing 31 and the outer peripheral surface of the mixing tube 35. A cylindrical combustible gas filter 63 is provided in the filter chamber 62, and the filter chamber 62 is divided into a portion closer to the inner circumference and a portion closer to the outer circumference. The combustible gas passage 61 is connected to the outer circumference of the filter chamber 62, and the mixing pipe 35 is provided with a plurality of passages 65 connected to the inner circumference of the filter chamber 62. The outlet of the passage 65 is connected to the mixed gas passage 29 formed by the small diameter hole 36.

A combustion-supporting gas passage 64 is provided on the rear end wall of the housing 31 and is connected to a chamber 66 at the rear of the housing 31 . The chamber 66 is a space that accommodates the cylindrical valve 53 and the spring 52, and the chamber 66 and the large diameter hole 3 are formed in the end wall 45 of the mixing tube.
A plurality of holes 69 are provided to connect the interiors of the chambers 9 (chambers 67). A filter chamber 72 is provided inside the large diameter portion 42, and a combustion supporting gas filter 73 is provided in the large diameter portion 42 to partition the filter chamber 72 into front and rear sections. Large diameter part 4
A plurality of holes 75 and 76 are provided in the rear and front parts of 2,
The rear part of the chamber 67 and the rear part of the filter chamber 72 communicate with each other through the hole 75, and the front part of the filter chamber 72 and the front part of the chamber 67 communicate with each other through the hole 76. The front end of the chamber 67 is the mixing tube 35
It is connected to the middle of the passage 65 (mixing section 13) via a passage 77 inside. In addition, 78 is an annular gasket, and hole 39
The large diameter portion 42 is provided at an annular stepped portion in the middle of the inner peripheral surface thereof, and in the illustrated state, the outer peripheral portion of the front end of the large diameter portion 42 is seated on the gasket 78.

Next, the operation will be explained. In a normal thermal spraying state, the passage 61. in FIG. 3 runs from the feeder 1 in FIG. 1 through the controller 2.
Combustible gas and combustion-supporting gas are sent to 64, respectively. The combustion-supporting gas flows from passage 64 through chamber 66 into the rear of chamber 67 and further into filter chamber 72 . At the front of the chamber 67, it flows into the mixing section 13 via a passage 77. Flammable gas is in passage 6
1 flows into the mixing section 13 via the filter chamber 62, and after being mixed with the combustion supporting gas in the mixing section 13, the passage 65,
The flame reaches the nozzle 80 at the tip of the burner tube 17 through the passage 29, and when ignited, it becomes a flame from the nozzle 80 and is ejected to the outside.

When backfire occurs, that is, when flame flows back from the crater 80 to the passage 29 side, each part operates as follows. First, in the second invention, when backfire occurs, the actuating body 4
Since high pressure is applied to the front end surface 41a of 1 from the passage 29 side,
The entire actuating body 41 moves rearward, and the groove 60 lines up inside the ball 59.

Then, the valve 53 biased by the spring 52 pushes the ball 59 down into the groove 60 as shown in FIG. 5 by the inclined cam surface 57 in FIG.
The valve 53 overcomes the sliding resistance caused by the ball 59 and moves forward, and the hole 69 is closed by the end face of the flange 55 of the valve 53.

Therefore, the supply of combustion-supporting gas from chamber 66 to chamber 67 is stopped, and the flashback is extinguished.

Furthermore, even if the flame attempts to enter the chamber 66 before the fire is extinguished, the flame propagation speed will be significantly reduced when the flame passes through the filter 73 shown in FIG. never reach it.

Next, in the first invention, when flame enters the passage 29 due to backfire and the internal temperature rises, the flashback detector 2 shown in FIG.
It is detected by the temperature sensor 27 of 6 and the controller 25
According to the signal from the controller 25, the combustible gas supply valve v2 closes and the inert gas supply valve v4 opens, and after a time limit, the combustible gas supply valve vl closes and the valve v3 opens. By opening, the supply of flammable gas and combustible gas to the mixing section 13 is stopped, and the passage 22.
Inert gas is supplied via channel 12.13 to mixing section 13 via channel 12.13. Therefore, this operation can also instantly extinguish the flashback. Note that the inert gas supply valves v3 and V4 are closed during normal thermal spraying.

As explained above, in the first invention, flashback is detected by the flashback detection device having the temperature sensor 27, and the valves l and v2 of the combustible gas supply line 12 and the combustible gas supply line 16 are closed. This allows backfires to be extinguished instantly. Further, in this invention, as in the illustrated embodiment, inert gas is supplied at the time of flashback, so that flashback can be extinguished more quickly and reliably.

According to the second invention, the cylindrical valve 5 of the combustion-supporting gas supply line is operated by the actuating body 41 driven by high pressure at the time of flashback.
3 (check valve) is closed, this also makes it possible to instantly extinguish the flashback.

In the embodiment, an inert gas is supplied to the inert gas supply line, but the purpose of the present invention can also be achieved by supplying an inert gas containing oxygen (for example, air) instead of an inert gas alone. can be almost achieved. In this case, it is cheaper than using an inert gas alone.

The present invention can also be applied to devices that use flammable liquid (oil) instead of flammable gas.

[Brief explanation of the drawing]

1M is a general configuration explanatory diagram of a thermal spraying apparatus, FIG. 2 is a schematic explanatory diagram of an embodiment of the present invention, FIG. 3 is a cross-sectional explanatory diagram showing an example of a burner structure used in carrying out the present invention, Figure 4 shows the operation of the check valve in the burner shown in Figure 3 (open state).
The explanatory diagram, FIG. 5, is an explanatory diagram of the operation (closed state) of the check valve □ in FIG. 3. 12... Flammable gas line, 13... Mixing section, 16
... Combustion support is Sline, 17... Burner pipe, 27...
-Temperature sensor, 41... Piston, 53... Valve (check valve), 80... Crater, Vl, v2... Valve.

Claims (3)

[Claims] (1) Connect the flammable fluid supply line and the combustion-supporting gas supply line to the tanker through the mixing section, and connect the inert gas supply line to the combustible fluid connection line and the inert gas supply line to the combustion-supporting gas supply line. When the mixed gas supply lines of active gas or inert gas and combustion supporting gas are connected and a flashback detection device installed in the burner detects flashback, the detection signal activates the control valve of each supply line. h] Use inert gas instead of flammable fluid in the flammable fluid supply line, and use inert gas or inert gas and combustible gas instead of combustion-supporting gas in the combustion-supporting gas supply line. A thermal spray gunner configured to supply a mixed gas of: (2) A flashback that connects the flammable fluid supply line and the combustion-supporting gas supply line to the nono-ner crater via the mixing section, and has a moving body in the burner that is activated by the pressure increase during flashback. A detection device is provided, and the movable body is linked with a check valve in the combustion-supporting gas supply line, so that when flashback occurs, the check valve is instantly closed by the operation of the movable body to stop the supply of the combustion-supporting gas. A thermal spray burner characterized by being configured as follows. (3) Connect the flammable fluid supply line and the combustion-supporting gas supply line to the fuel tanker via the mixing section, and connect the inert gas supply line to the flammable fluid supply line and the inert gas supply line to the combustion-supporting gas supply line. When the mixed gas supply lines of active gas or inert gas and combustion supporting gas are connected and a flashback detection device installed in the burner detects flashback, the detection signal activates the control valve of each supply line. Inert gas is used instead of combustible fluid in the flammable fluid supply line, and inert gas or a mixture of inert gas and combustible gas is used in the combustible gas supply line instead of combustible gas. In addition to supplying
The flammable fluid supply line and the combustion-supporting gas supply line are connected to the burner mouth part through the mixing part, and the burner is provided with a flashback detection device having a movable body that is activated by a pressure increase during flashback, and A check valve in a combustion-supporting gas supply line is linked to a moving body, and in the event of a backfire, the check valve is instantly closed by the operation of the moving body to stop the supply of combustion-supporting gas. Features a thermal spray burner.